For a 16×24 picture, choose a mat whose opening is about 1/8 to 1/4 inch smaller than the artwork on each side.
The mat window must overlap the art, not expose its edges. Measure the artwork first, then subtract the overlap from each dimension to get the opening. For a true 16×24 print, the opening should measure roughly 15 3/4 x 23 3/4 inches so the mat covers the print’s edge by at least 1/8 inch on every side. Sizing the opening exactly to the image is the most common mistake because it lets the print fall through or shows raw edges.
Why The Mat Opening Must Be Smaller Than The Artwork
The mat’s window is not a frame; it is a cover that must hold the print in place and hide uneven trim or rough edges. Picture-framing instruction from Logan Graphic Products says the mat should overlap the artwork by at least 1/8 inch on all sides, with many framers using 1/4 inch for extra safety, especially when the print has a white border or wavy edges. For a 16×24 print:
- 1/8-inch overlap: opening of 15 3/4 x 23 3/4 inches (standard, pairs with a 20×28 frame).
- 1/4-inch overlap: opening of 15 1/2 x 23 1/2 inches.
Picking Border Widths To Reach A Standard Size
Once the opening is set, add border width on all four sides to reach the mat’s outer dimension, which should match the frame’s rabbet opening (measured from the back along the inside lip). Adding a 2-inch border to the 15 3/4 x 23 3/4 window produces a 19 3/4 x 27 3/4 mat. Since that is not standard, most guides round up to the next common ready-made option: a 20×28 mat and frame. The slightly larger outer mat still hides behind the frame’s rabbet.
Larger borders of 2.5 to 4 inches are common for bigger artwork and give a more gallery-like presence; a skimpy 1.5-inch border can feel like an afterthought. If you want a frame with the mat included, a roundup of 16×24 frames with mats already sized shows how border widths look on finished options.
Opening Placement And Prints With Borders
Mat openings are not always centered. Published framing guides note that bottom-weighting the opening (making the bottom border slightly wider than the top) creates visual balance, though centered openings look fine for most home displays. If your 16×24 print has a white border, signature margin, or irregular edges, the mat can cover more than the 1/8-inch minimum; trimmed or damaged artwork should get a larger overlap so the mat hides the flaw entirely. The visible image area shifts based on opening position, so place the window over the part of the print you actually want to show.
| Mat Opening | Border Width | Outer Mat Size |
|---|---|---|
| 15 3/4 x 23 3/4 in | 2 in on all sides | 19 3/4 x 27 3/4 in (non-standard) |
| 15 3/4 x 23 3/4 in | Rounded to fit standard | 20 x 28 in (standard frame size) |
| 15 1/2 x 23 1/2 in (1/4-in overlap) | 2.5–4 in for gallery look | Varies with frame choice |
No-mat framing works only when the frame’s opening matches the print exactly at 16×24, leaving edges fully exposed. That only suits clean, straight cuts with no border you want to hide.
Measuring The Frame And Avoiding Common Mistakes
Order matters: pick the frame first, measure its rabbet opening from the back, and size the mat to fit that space. Choosing an outer mat size before knowing the frame’s inner dimensions forces you to hunt for a frame that may not exist. Logan’s framing guide stresses that the rabbet must be slightly larger than the combined thickness of the mat, glass, and backing; if too thick, the back points won’t seat and the glass can bow. Measuring the artwork, then the frame, then cutting the mat to bridge them prevents waste.
For a 16×24 picture, the practical takeaway: cut or order a mat with a 15 3/4 x 23 3/4 opening, use a 2-inch or wider border on each side, and look for a 20×28 frame. Buying mat and frame together removes guesswork around rabbet depth and outer dimension mismatch. Need a shortcut? A Logan Graphic measuring and sizing guide walks through the same steps with visuals.
FAQs
What size mat opening do I need for a 16×24 print?
A 15 3/4 x 23 3/4 inch opening is the standard recommendation, leaving a 1/8-inch overlap on every side to hold the print securely and hide rough edges.
What outer mat size fits a 16×24 picture in a ready-made frame?
A 20×28 mat and frame combination is the most common standard choice. The 15 3/4 x 23 3/4 opening with 2-inch borders produces a 19 3/4 x 27 3/4 mat, which sits neatly behind the rabbet of a 20×28 frame.
Can I frame a 16×24 print without a mat?
Yes, if the frame’s opening measures exactly 16×24 inches. That works only when the print has clean, straight edges and no white border to hide, since the mat’s overlap job is gone entirely.
References & Sources
- Logan Graphic Products. “Measuring & Sizing for Picture Framing.” Explains the 1/8-inch overlap rule and rabbet measurement.
- Logan Graphic Products. “Measuring Mats for Picture Framing.” Details how to determine opening size and border width.
- Southern Arizona Watercolor Guild. “Adjusting Mat Sizes for Standard Frame Sizes.” Lists the 15 3/4 x 23 3/4 opening for 16×24 art in a 20×28 frame.
